Re: ISSUE-268 (nigel): Purpose of new draft wording in 12.2.1 is unclear [TTML 1.0]

On Mon, Aug 12, 2013 at 3:53 AM, Nigel Megitt <nigel.megitt@bbc.co.uk>wrote:

>  Apologies, I agree significant is defined.
>
>  However, I don't understand why in 12.1.7 it is sufficient merely to use
> the word significant to express this concept whereas in 12.2.1 it is also
> clarified that the agent instances must appear in the same Document
> Instance – surely this is a tautology, or if not the same qualification
> applies in both 12.1.1 and 12.1.7. It may be clearer to move the 'in the
> same Document instance' phrasing to the definition of significant in 12.1.5.
>

You are correct that the new clarification implies the same Document
Instance. The latter language, about the same Document Instance, preceded
the new clarification about referencing a "significant" agent, and when I
made the new clarification, I felt that it didn't invalidate the
pre-existing language, and that it wouldn't hurt to leave it in.

If you think it better to do so, I could remove the the "same Document
Instance" language, which would be more correct than propagating this old
language to 12.1.5.



>
>
>   On 09/08/2013 17:44, "Glenn Adams" <glenn@skynav.com> wrote:
>
>   Not a bug. See 12.1.5 for meaning of "significant" in this context:
>
>  A ttm:agent metadata item is considered to be significant only when
> specified as a child of the head element or as a child of a metadata element
> child of the head element.
>
>
> On Fri, Aug 9, 2013 at 5:30 AM, Timed Text Working Group Issue Tracker <
> sysbot+tracker@w3.org> wrote:
>
>> ISSUE-268 (nigel): Purpose of new draft wording in 12.2.1 is unclear
>> [TTML 1.0]
>>
>> http://www.w3.org/AudioVideo/TT/tracker/issues/268
>>
>> Raised by: Nigel Megitt
>> On product: TTML 1.0
>>
>> The edit to 12.2.1 described in
>> https://dvcs.w3.org/hg/ttml/raw-file/default/ttml10/spec/ttml-changes.html#change-history-per-to-rec-23section 1.1 adds the word "significant" into the sentence:
>>
>> If specified, a ttm:agent attribute must reference significant ttm:agent
>> element instances that appear as a descendent of the same Document Instance
>> as that of the referring element.
>>
>> The intended additional meaning introduced by this edit is unclear. The
>> text already says that the referenced agent must appear within the
>> document, and there are restricted locations where it can be. I propose
>> either reverting the edit or adding text to explain what distinguishes a
>> "significant" agent from any other kind.
>>
>>
>>
>>
>>